1. Field of the Invention
The invention relates to a coke-oven battery of the type having a continuous oven roof and a plurality of uprights on the so-called machine or pusher side and on the coke side of the battery. These uprights are linked together by means of ties, e.g. tie-bolts, arranged inside pipes installed in the oven roof.
2. Description of the Prior Art
In the structure of a coke-oven battery described above, the uprights and ties form a frame, typically of steel, which supports the refractory structure of coking chamber, combustion chambers and heat regenerators. The ties are typically tie-bolts.
Because, as the temperature of the structure changes, different degrees of expansion occur in the frame and the refractory structure, it is conventional for the tie-bolts to be prestressed using resilient elements to ensure that the refractory structure remains intact under pressure. The freedom of movement relative to the oven-roof structure which the ties need for this purpose makes it advisable for the ties to be arranged inside pipes in the roof. For this purpose, the ties are generally recessed into the oven roof, which is around 1 to 11/2 m thick, at a depth for example about 100 mm from the top of the roof.
In order to ensure maintenance of the pre-stress of the tie bolts it is necessary to check the tension in the ties at regular intervals and where necessary to correct it. In view of the large number of ties and their inaccessibility, considerable difficulties are encountered in carrying out sufficiently regular checks on these tension values. In addition to this, the temperature in the ties may increase considerably in a very short time as a result of leakages through the oven roof or flames shooting out when the coking chambers are opened. These factors may give rise to a fairly sudden and sharp drop in tension in one or more ties, as a result of which the uprights connected to these ties in the battery may move and in turn give rise to further leakages, e.g. between the uprights and the refractory structure. It has also appeared that the tension may likewise undergo sudden, sharp increases as a result of which the ties may break.
Temperature measurements taken on the ties in a coke-oven battery have indicated values in the region of 400.degree. C. with major differences in temperature between individual ties. In view of the length of the ties, which may vary from around 12 to 16 meters, these increases in temperature and temperature variations within the ties may result in substantial variations in tension which resilient structures have difficulty in absorbing.
GB No. 667,566 discloses passing cooling fluid through hollow tie rods in a coking oven, while GB No. 428,268 proposes passing air either through the rod or through an annular space around the rod.
DE No. 231,043 describes passing water through a pipe surrounding an oven tie rod.
These cooling methods, though able to provide good cooling of the tie rods, have the disadvantage of requiring means for supply of the coolant, which means may require maintenance and control, and of leading to possible problems of corrosion.